Nigel Holness, London Underground’s director of network operations, said: "I apologise to customers whose journeys on the Tube were disrupted this morning due to a power failure at Aldgate East as well as by signal failures at Barking and Wembley Park.

"Our engineers were on site and worked hard to restore services as soon as possible.

"The derailment of a South Western Trains service at Wimbledon has also affected the District line, which remains suspended between Parsons Green and Wimbledon.

"Our engineers are supporting Network Rail with recovery work, which is likely to continue for the rest of the day."

Rail passengers are advised to check National Rail Enquiries for updates.

A South Western Railway spokesman said: "The slow-speed rear-axle derailment on the 04.54 Basingstoke to Waterloo service occurred between Wimbledon and Wimbledon Park. Lines are open but there is some congestion and delays to South Western Railway services into London this morning.

"The train is 8 carriages in length and it was the the rear axle of the 8th coach which came off the track at slow speed.

"The passengers on the train were evacuated by London Fire Brigade to Wimbledon station car park, with everyone off the train by 08.15. London Ambulance Service reported four passengers with injuries, none of which required hospital treatment.

"From the car park, passengers were taken to the station where they received assistance from members of staff."